The FAA has issued a revision of Special Airworthiness Information Bulletin NM-08-27 to more accurately reflect information developed by the SAE G-12F catalytic oxidation of carbon brakes working group. The group has “determined that the issue of thermal oxidation is a separate technical issue with carbon brakes and is not a direct result of the carbon material being exposed to the alkali metal runway de-icers.” The revised SAIB, NM-08-27R1, notifies operators of transport-category aircraft that a switch to more environmentally friendly organic salt runway de-icer fluids could cause fluid in contact with carbon brakes to soften “the carbon, causing it to flake and crumble over time, reducing the life and long-term efficiency of the brakes themselves. As a result, there is a danger of possible brake failure during high-speed aborted takeoff or dragged brake during normal takeoff (and subsequent overheat, once airborne) or excessive vibration during any ground operation.” The SAIB isn’t mandatory, but the FAA recommends more frequent inspection of affected brakes and extra attention during regular brake removals.